Setting up nginx and lua fastcgi on Debian Squeeze
The available pages I can google about this seem overly complicated. This one documents setting up nginx to run lua scripts on Debian Squeeze. These instructions are derived from http://www.unreliablepollution.net/p/other/howto-nginx-and-lua and a dozen remedial googleings.
aptitude install nginx
The config in /etc/nginx is good in squeeze. We will need to add the fastcgi handler, but that is to be expected. (I edited it to pull the root up to /var/www instead of in an nginx-default subdirectory.)aptitude install liblua5.1-wsapi-fcgi-1
There is also a ‘0’ version, but I took 1 on the theory that newer is better.aptitude install liblua5.1-coxpcall0
liblua5.1-wsapi-fcgi-1 probably needs a dependency on this. Things will go poorly for you without it.aptitude install lua5.1
Can’t forget that.aptitude install spawn-fcgi
Older instructions talk about libfastcgi-dev, but it isn’t available and I think they just wanted spawn-fcgi out of it anyway.Put a Lua file in /var/www/hello.lua
The WSAPI is a little strange. Apparently you don’t just print your output, but rather coroutine.yield() it. I used this example program from http://keplerproject.github.com/wsapi/manual.html …module(…, package.seeall)
function run(wsapi_env) local headers = { [“Content-type”] = “text/html” }
local function hello_text() coroutine.yield(”<html><body>”) coroutine.yield(”<p>Hello Wsapi!</p>”) coroutine.yield(”<p>PATH_INFO: “ .. wsapi_env.PATH_INFO .. “</p>”) coroutine.yield(”<p>SCRIPT_NAME: “ .. wsapi_env.SCRIPT_NAME .. “</p>”) coroutine.yield(”</body></html>”) end
return 200, headers, coroutine.wrap(hello_text) end
spawn-fcgi -a 127.0.0.1 -p 9100 -F 4 -- /usr/bin/wsapi.fcgi
Now we have handlers on port 9100. This will need to be in /etc/init.d/blahblahblah but this will do for now.
Note: spawn-fcgi silently fails if you get the command wrong. Do a “ps” and make sure they are there. You will have a section like this if it succeeds…
18554 ? Ss 0:00 lua5.1 /usr/bin/wsapi.fcgi
18555 ? Ss 0:00 lua5.1 /usr/bin/wsapi.fcgi
18556 ? Ss 0:00 lua5.1 /usr/bin/wsapi.fcgi
18557 ? Ss 0:00 lua5.1 /usr/bin/wsapi.fcgiEdit /etc/nginx/sites-available/default to know how we want .lua files handled. I put in this section
location \~ \^(.+\.lua)(.*)\$ { root /var/www/; fastcgi_pass 127.0.0.1:9100; fastcgi_index index.lua; fastcgi_split_path_info \^(.+\.lua)(.*)\$; fastcgi_param PATH_INFO \$fastcgi_path_info; fastcgi_param SCRIPT_FILENAME \$document_root\$fastcgi_script_name; include fastcgi_params; } Be careful! Make ‘root’ match your root!Restart nginx.
/etc/init.d/nginx restartLoad http://YOURSERVER/hello.lua in your browser. You should get something along the lines of:
Hello Wsapi!
PATH_INFO: / SCRIPT_NAME: /hello.lua
Celebrate!
Now my thoughts: This may be more than I wanted. I have to think about the implications of a scrutinizer layer above my Lua program. I really wanted to just blast my standard output back up the fastcgi socket. All this yielding seems strange.